$8\%)$Problem $5$: You have a horizontal grindstone $($a disk$)$that is $94$kg$.$has a $0\mathrm{.}36$m radius, is turning at $89$rpm in the positive direction$),$and you press a steel axe against the edge with a force of $17$N in the radial direction. F A $50\%$Part $($a$)$Assuming that the kinetic coefficient of friction between steel and stone is $0\mathrm{.}20.$calculate the angular acceleration of the grindstone in rad$/$s$2.>$A $50\%$Part $($b$)$What is the number of turns, N$,$that the stone will make before coming to rest?